LONDON, Ont. — Ontario’s beekeepers lost 58% of their bees last winter, a new report says.

The provincial death rate was more than three times the average for the rest of Canada and well above the 15% loss for a typical winter.

The report from the Canadian Association of Professional Apiculturists identified three possible factors for the steep losses in Ontario: starvation from lack of food caused by the harsh winter, exposure to pesticides and parasites.

“I had one of my worst years. It was either my worst or second-worst. We lost 35% here,” said Dan Davidson, president of the Ontario Beekeepers’ Association.

“It is the highest documented level of winter mortality that we have had in Ontario as a province,” said Paul Kozak, provincial apiarist for the Ministry of Agriculture and Rural Affairs. “We have other years that have been high, but not as high as 58%.”

Bees cluster together in the winter months, lying dormant until spring. Beekeepers often insulate their hives and check to make sure the bees in the colony are healthy.

Generally, a loss of about 15% over the winter is described as acceptable by most beekeepers, the Canadian Association of Professional Apiculturists said.

Though Davidson recognizes the brutal conditions last winter were a factor in the mortality rate, he also said that declining bee health from neonicotinoid insecticides and mites is having an effect as well. Unhealthy colonies have a more difficult time adapting to the strain of winter dormancy, he said.

“You get two things piling on top of each other, it gets difficult. And then you try and get through a winter.”

The Ministry of Agriculture and Rural Affairs is taking a closer look at why this year’s number was so disproportionately high.

In the meantime, financial support is available for the hardest hit beekeepers from a provincial program introduced in April.